Refrigeration



Aug. 31, 1937. w, G, KGEL 2,091,595

REFRIGERATION Filed May 7. 1936 Y Bly. 4. INVENTOR A14 ATTOBNEY.

raientea Aug. t, i937 UNITED PATE REFRHGERATIGN wilhelm Georg Kagel, stockholm, sweden, as-

signor, by mesne assignments, to Servei, Inc., New York, N. Y., a corporation of Delaware Application May 7, 1936, serian No. '18,331

In Germany May 31, 1935 i claim. (ci. ca -ias) in a storage compartment of a refrigerator to a temperature suitable for the proper preservation of comestibles.

It is a further object to provide a cooling element which is simple in structure and having substantially independent heat transferwith respect to its air cooling and water freezing parts.

In carrying out the invention, I provide a cooling element comprising an iron pipe coil to which heat is conducted by a sheet metal structure having heat conductivity greater than that of iron. Part of the sheet r'netal structure is utllized for heat transmission to the coil from freezing chambers surrounded by the coil, and another part of the sheet metal structure which may be in the form of a casing around the coil is utilized for conducting heat to the coil from air in a refrigerator storage compartment. That part of the sheet metal structure utilized for ice freezing purposes may form shelves for receiving ice trays or the like in the freezing compartment and is secured in good thermal conductive relation with the pipe coil. The casing forming the air cooling surface may be arranged in a different thermal conductive relation with the pipe coil, and I provide simple means for predetermlnlng the relationship between the air cooling casing and the pipe coil,

The invention, together with the objects and advantages thereof, will be more fully understood upon reference to the following descripg tion taken in connection with the accompanying drawing forming part of this specificatlonand'of which: j I

Fig. 1 is a fragmentary sectional view of a refrigerator showing 'in front elevation a cooling element embodying the invention;

Fig. 2 is a view taken on line 2 2' in Fig. l;

Fig. 3 is a sectional view taken on line 3;-3 in Fig. 2;

Fig. 4 is'a detail section taken on line in Fig. 2; and

Fig. 5 is a detail section taken on line 5-5 in Fig. 3.` v

A refrigerator cabinet I0 providing a thermally insulated storage compartment II may be prothe absorber and the generator.

vided with a uniform pressure typeabsorption refrigeration apparatus of a type generally like that disclosed in United States Patent No. 1,609,334, having a cooling element l2 constructed and arranged in accordance with the present invention. The cooling element i2 comprises an iron pipe coil i3 formed with a plurality of alternate substantially horizontal and vertical U-shaped turns enclosing a freezing area open at the front end. The front end @il of the coil l@ is connected by a conduit I5 to one part of a gas heat exchanger I6 and the lower end ll of the coil I3 is connected to another part of the gas heat exchanger i5, the gas heat exchanger it being-a part of the refrigerationapparatus whichl is not further illustrated here. Briefly, however, in this type of refrigeration system, an inert gas such as hydrogen is circulated between an evaporator and an absorber, and an absorption liquid such as Water is circulated between In the generator, a cooling fluid or refrigerant such as ammonia is vaporized out of solution in the absorption liquid by heat. The vapor is liquefied in a condenser and the refrigerant liquid is conducted to the evaporator in which'the liquid evaporates and diffuses into the hydrogen, producing a refrigeration eiect. In the absorber, re-- frigerant vapor is'absorbed out of the hydrogen into weakened absorption liquid. The gas heat exchanger I6 is arranged in the circuit between the evaporator l2 and an absorber, not shown. l

Weak gas flows from the gas heat exchanger I6 through. conduit I5 to the upper end I4 of the evaporator coil i3. Liquid refrigerant is also introduced into the upper end I4 of the evaporator coil I3 by means of a conduit I8. In the evaporator coil i3, the liquid refrigerant flows downwardly, evaporating and diffusing into the inert gas. The resulting mixture or rich gas flows from the lower end Il'of the evaporator coil I3 into the gas heat exchanger I6 and thence back to the absorber, not shown.

The pipe coil I3 is constructed and arranged for continuously downward ow of liquid therethrough, but the generally horizontal loops of the pipe coil have leg portions which are substantially opposite one another in the same horizontal plane but have a slight slant in opposite directions. Between the leg portions of the horizontal loops of the pipe coil I3 are shelves or partitions, each formed by an upper plate I9 and a lower plate 20, as may be seen in Figs. 4 and 5. The side edges of the plates I9. and 20 are suitably formed as by stamping to engage therebetween the opposite legs of a horizontal loop of the evaporator coil when the plates I! and 20 are secured together. The plates I9 and 20 may be secured together and in close thermal contact 5 with the. pipe coil by means of rivets 2l and also by tabs 22 and 23. 'I'he tabs 22 and 23 are formed on the outer edges of the plates I 9 and 20 and are extended through suitable slots 24 in an outer sheet metal casing'25 and overturned 10 on the outside of the casing 25. The plates I 9 and 20 and the outer casing 25v may be of copper or tin or any other material of good heat conductivity. The several compartments formed by the shelves comprising plates I9 and 20 may be provided with side walls formed by sheet metal inserts 26 which may also be of copper, tin, or other metal of good heat conductivity.

The outer casing 25 encloses the sides, top, and rear of the cooling element and provides a .20 heat transfer surface for cooling of air inthe refrigerator compartment Il. Whereas the shelves formed, by plates I9 and 20 are secured in good thermal contact with the evaporator coil I3 the full length of each side of the. shelves, 25 the outer casing 25 is brought into thermal conductive relation with the evaporator coil only by means of the connections formed by the previously described tabs 22 and 23. Therefore, the amount of heat transfer from the casing 25 30 to the coil I3 Amay be varied relative to the heat transferto the coil I3 from the shelves formed by plates I9 and 20 in accordance with the numfber of connections formed by tabs 22 and 23. In other words, the greater the number of con- 35 nections formed by tabs 22 and 23, the greater will be the conduction of heatI from the casing 25 to the coil 63. Therefore by providing a certain number of such connections, a given ratio of heat conduction to the coil I3 may be obtained with respect to the freezing compartments and the air in the refrigerator storage compartment.

It will be understood that various changes may be made within the scope of the invention. For instance, instead of usingtwo plates. I9 and 20, a single vplate ofsuitable thickness may be used. and the side edges of `the single plate folded around the straight portions of the coil loops and` riveted or otherwise clamped thereto in good Athermal conductive relation. Also, the outer casing 25 maybe provided with fins for increasingl the heat transfer surface thereof. Therefore, the invention is not limited except as indicated inthe following claim.

l What isclaimed is:

A cooling element comprising an iron pipe coil adapted for circulation of inert gas and continuously downward ilow of liquid therethrough, said coil comprising a plurality of substantially horizontal superposed U-shaped turns, shelves each formed by two sheets of metal having greater conductivity than iron, said sheets being secured together and having their side edges formed to engage opposite legs of said coil turns in good thermal contact, saidA sheets of metalv having tabs extending outwardly from their side 1 edges, and a sheet metal casing around said coil forming a freezing chamber open at the open end of said turns, said casing being provided with slots through which said tabs extend for securing said casing.

A WILHELM GEORG 

